Worldwide countries face growing challenges of social inclusion amid the massive influx of migrant populations into large cities. Planning scholars have long been intrigued by the role of the physical design of urban neighborhoods in fostering a cohesive and inclusive urban society. However, empirical research on the effects of public spaces on promoting intergroup solidarity and inclusion has been less systematic and produced far less conclusive findings. Using Beijing, China, as a case study, this research contributed to this ongoing debate with an empirical investigation of the extent to which neighborhood physical environment – specifically, accessibility to different types of urban public spaces -- contributes to a more positive attitude among native residents toward migrant social inclusion through fostering more frequent neighborly social interaction. Based on a large-scale survey conducted in 2017, we adopted structural equation modeling analysis and found more significant effects of accessibility to quasi-public spaces than typical public spaces in promoting both neighborly interactions and inclusiveness attitudes. We discuss the theoretical and policy implications for the role of neighborhood physical environment in the pursuit of building inclusive cities.